#CalStatisticsV1.py
def getNum():   #获得用户不定长度的输入
    nums=[]
    iNumStr=input("请输入数字(回车退出):")
    while iNumStr !="":
        nums.append(eval(iNumStr))
        iNumStr=input("请输入数字(回车退出):")
    return nums

def mean(numbers):    #计算平均值
    s=0.0
    for num in numbers:
        s=s+num
    return s/len(numbers)

def dev(numbers,mean):   #计算方差
    sdev=0.0
    for num in numbers:
        sdev=sdev+(num-mean)**2
    return pow(sdev/(len(numbers)-1),0.5)

def median(numbers):    #计算中位数
    sorted(numbers)
    size=len(numbers)
    if size%2==0:
        med=(numbers[size//2-1]+numbers[size//2])/2
    else:
        med=numbers[size//2]
    return med

n=getNum()
m=mean(n)
print("平均值:{},方差:{:.2},中位数:{}.".format(m,dev(n,m),median(n)))
